JPS59171264A - Picture processor - Google Patents

Abstract

PURPOSE:To execute excellently also the reproduction of an intermediate tone without losing sharpness of a character or the like by overlapping multi-color of a picture data resolved in color to reproduce a color picture. CONSTITUTION:A character code string signal as a character picture data 101 and a picture signal 105 attended with an R, G, B color identification signal 104 and V/H synchronizing signals 106V, 106H as a color picture data are applied. Further, a character code picture in a specific region read from a character code buffer 10 is converted into a dot data by a character generator 9 and stored in a designated area in an image memory 8. Further, a color intermediate tone picture consists of the signals 104, 106V, 106H and a density data 105 and stored in an image memory 21. Then, each picture signal (yellow, magenta, cyan and black) is read sequentially and a full color picture is obtained by overlapping all color pictures.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field The present invention relates to an image processing apparatus that obtains a color image by combining a color image including a halftone image and a line image such as a character image.

BACKGROUND ART Conventionally, as image processing apparatuses configured to reproduce halftones using dot images, apparatuses based on inkjet printers, thermal transfer printers, laser beam printers, and the like are known. In order to reproduce halftones, such devices use a dither method, a density pattern method, etc., which reproduce halftones by modulating the dot diameter or by modulating dots within a small area. In particular, with color laser beam printers, it is difficult to change the spot diameter of the writing laser and it is virtually impossible to modulate the dot diameter, so dithering is mainly used to reproduce halftones. There is. However,
For images with clear brightness and darkness, such as letters and lines, dithering has the drawback that the edges become blurred or the density of solid areas decreases, resulting in a loss of sharpness.

On the other hand, image data sent from a color video camera, image file, etc. is stored once in a buffer memory within a color printer and then printed out, so it has versatility in terms of transfer speed. Then, in order to print out a dot image according to the density data of the transferred image, dither processing is performed and the image is converted, but in one type of image buffer memory, characters and halftone images , so that the character image loses its sharpness due to such dither processing.

OBJECTS In view of the above-mentioned points, it is an object of the present invention to provide an image processing apparatus configured so that halftones can be well reproduced without losing the sharpness of characters and the like.

Example Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing an entire embodiment of the present invention.

The illustrated image processing device receives character code string signals as shown in FIG. 2 as character image data 101, and R, G, and B color identification signals 104 as shown in FIG. 3 as color image data, as well as vertical , horizontal synchronization signal 106V, 10
An image signal 105 with 6H is supplied from outside. Further, image trimming position designation signals 1102, 103,
107 and 108 are also supplied from outside.

FIG. 2 shows a character image data string signal, which includes character string data C10, C11, C12, . . . in the first line following the leading identification code ITOP of one image. Also,
A RET code is inserted after the last character of each line. Therefore, when a RET code is detected on the receiving side (that is, on the image processing apparatus side), a line feed is performed. In FIG. 2, R1 is the RET code of the first line, R
2 is the RET code on the second line. After the last line in a single character image, the end code for the single character image is IEND.
is inserted to end one character image data. This image processing apparatus identifies the end of a single character image by receiving this IEND code.

The character image data 101 supplied as described above is stored in the character code puffer 10 for one screen. At this time,
The above-mentioned special code (eg, ITOP code, RET code, IEND code) is decoded by the character code decoder 11, and sends out a storage start/line feed command signal 109 and a storage end signal 110 for storing character images.

FIG. 4 shows an example of a character screen stored in this manner. Here, each letter A, B, ... a, b, c, ...
... is represented by, for example, an 8-bit ASCII code. Since this image processing apparatus employs a laser beam method using dot images, it is necessary to convert the character code string described above into a dot form. Therefore, in this embodiment, the character generator 9 is used to perform such dot conversion. The character generator 9 is the same as a well-known one, so a description thereof will be omitted. At this time, an area information signal 102 indicating which area of a single character image supplied from the outside should be printed out (that is, information specifying a matrix of character code images) is provided from an external device.

For example, in the character code image shown in FIG. 4, the printout start character and end character are (m1, n1) to (
m2, n2), the area within the thick line shown in the figure is read from the character code buffer 10. Then, printout designation information (m
1, n1) and (m2, n2), the read position designation circuit 17 and read address generator 18 generate a read address for the designated area.

On the other hand, a designation signal 103 is used to designate which region of the print image the character image region designated as described above should be printed out. The write area for printout is given by the pixel number and scanning line number (m1', n1') at the write start position and the same number (m2', n2') at the write end position, and is controlled by the image memory write position designation control circuit. 15 and the image memory address generator 14.
A write address is generated.

The character code image in the specific area read out from the character code buffer 10 in this manner is converted into dot data by the character generator 9, and stored in a designated area to be printed out in the image memory 8. This situation is shown in FIGS. 5A and 5B.

Next, processing of color halftone images supplied as density data of each color of R, G, and B will be explained. This color halftone image includes R, G, and B color identification signals 104 as shown in FIG.
, vertical and horizontal synchronization signals 106V, 106H, and density data (i.e., image signal) 1 for each pixel of the image.
05. Each color image is stored in a buffer memory 28-1 for each color according to the R, G, and B color identification signals 104.
, 28-2, and 28-3, respectively.

The synchronization signals 106V and 106H are supplied to the storage address generator 32, and the address selector 30 outputs the necessary addresses to the image buffer memories 28-1 and 28-1.
8-2, given to 28-3. Thus, each color image is stored in the image buffer memory 28-1, 28-2, 28-3.
are stored in each.

Thereafter, in the same way as when reading from the character code buffer 10, an area in which a halftone image is to be printed out is designated by a signal 107 supplied from the outside. this is,
The printout start point, pixel number, and scanning line number are given, and the corresponding image memories 28-1 and 28-2
, 28-3 are generated from the read address generator 31.

When reading, the image buffer memory (stores the B signal) 28-1 for yellow (Y), and the image buffer memory 28-1 for magenta (M
) image buffer memory (stores G signal)
28-7, Image buffer memory for cyan (C) (
The same pixels from 28-3 (store the R signal) are respectively Y,
They are read out simultaneously as M and C components. (Here B,
The color signals read out in this way are finally stored in the image memory 21 for halftone images. As described above, the writing start position is specified by a signal 108 supplied from an external source (not shown) so that the specified image area is printed out at the specified position. In response to this, the image memory write position designation circuit 23 and the image memory address generator 22
generates an address in the image memory 21 corresponding to the specified location. This operation is similar to that for the character image data described above.

Note that the image buffer memories 28-1, 28-2, 2
The color density data for each pixel read out from 8-3 is subjected to gamma conversion (density conversion) in accordance with the characteristics of this image processing apparatus in the gamma correction circuit 27, and is further subjected to masking processing ( 26) and U.C.
After being subjected to R processing (see 25) and then dither processing (see 24), it is stored as dot data in the specified position in the image memory 21 as described above. As is well known, dither processing refers to electrical processing that determines recording dots to be output by comparing the density data of each pixel with a threshold value in order to reproduce halftones.

This image processing device sequentially prints out a yellow image first, a magenta image second, a cyan image third, and a black image fourth, and then superimposes each color image to create a full-color image. Therefore, the storage capacity of the image memory 21 is sufficient for one image. Then, each time each color is printed, the above-described color processing and transfer to the image memory 21 are performed.

In order to read the data from the character image image memory 8 and the halftone color image image memory 21 and send it to the laser light modulation circuit 5, these image data are stored as dot data in the image memories 8 and 21, respectively, and The same address is assigned to the same pixel.

In this embodiment, the addressing of both image memories 8 and 21 is done by the image memory address generator 1.
4 is in control. That is, a read address is generated when images are stored in both image memories 8 and 21, and thereby dot data of characters and halftone images corresponding to the same pixel are sent out.

The dot data read from the image memories 8 and 21 are superimposed by the OR gate 7 to modulate the laser beam. The modulated laser light forms an electrostatic latent image on the photosensitive drum 1. The process of creating a print image is the same as that of a normal laser beam printer, and Y, M, C, BK (
4 types of developing devices (all not shown) for black)
is used selectively. Further, a signal 113 is a horizontal synchronizing signal sent from the laser beam detector 40 when the laser beam is irradiated with the laser beam, and causes image data reading from the image memories 8 and 21 to be performed in synchronization.

120 in FIG. 1 is a 4-bit signal specifying the color of a character image. This signal may be a signal from the host or a switch within the image processing apparatus. Here, each bit of the 4-bit color designation signal C0 to C3 is sequentially changed to Y, M, C,
It is compatible with BK. A character image of a desired color can be obtained by controlling character image output using a latent image formation signal 112 of a color corresponding to a designated bit.

For example (C0, C1, C2, C3) = (1, 1, 0, 0
), the character image will be output for Y and M, and the character will be a red image.

Normally, when a character image is combined with black BK, the character image appears more clearly in the halftone image more effectively. In this case, the color designation signals (C0, C1, C2, C3) are (0, 0,
0, 1).

FIG. 5 shows an example in which designated areas of a character image and a halftone image are individually moved, and these two images are combined. That is, by moving the area for each of the input images A and C, the resulting images B and D
The image B+D is obtained by combining the images.

Effects As explained above, according to the present invention, it is possible to synthesize a character image with a halftone image without impairing the sharpness of the character image, and moreover, it is possible to move the designated area for each of the character image and the halftone image separately. Therefore, it is possible to efficiently rearrange and synthesize character images and halftone images.

Further, according to the present invention, since character images can be input using code codes, connection with other devices is also possible, and a versatile image processing device can be obtained.

Further, according to the present invention, a character image can be made to have an arbitrary color depending on a halftone image as a background, and the reproducibility of the character image and the halftone image can be improved.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the entire embodiment of the present invention, FIG. 2 is a diagram showing an example of character image data, FIG. 3 is a diagram showing an example of color image data, and FIG. 4 is a diagram showing the character code buffer. FIG. 5 is a diagram showing an example of a stored character screen, and is a diagram showing an example in which designated areas of a character image and a halftone image are moved separately, and these two screens are combined. DESCRIPTION OF SYMBOLS 1...Photosensitive drum, 2...Lens 3...Reflection mirror, 4...Laser light source 5...Laser light modulation circuit, 6...Line buffer 7... - OR gate, 8... Character image memory 9... Character generator 10... Character code buffer 11... Character code decoder 12... Interface 14... Image memory... address generator 1
5... Image memory write position designation circuit 16.
... Control circuit 17 ... Read position designation circuit 18 ... Read address generator 19 ...
-Write address generator 20...Address selector 21...Image memory for halftone image 22...
Image memory address generator 23... Image memory write position designation circuit 24... Dither circuit, 25... UCR circuit 26... Masking circuit 27... Gamma correction circuit 28-1, 28-2, 28-3... Image buffer memory 29... Interface 30... Address selector 31... Read address generator 32...
・Write address generator 33... Read position designation circuit

Claims (1)

[Claims] 1. In an image processing device that inputs and processes color-separated image data and character image data, inputs the color-separated image data and reproduces a color image by overlapping multiple colors. and an image processing apparatus configured to input the character image data and to make the character image appear in a specific color. 2. The image processing apparatus according to claim 1, wherein the character image data can be combined with any part of the image data and output. 3. The specific colors include yellow, magenta, cyan,
2. The image processing device according to claim 1, wherein the color is black and a color obtained by superimposing a plurality of colors among these colors.